Which of the Following Statements Is Not Deductively Valid

question 19

Multiple Choice

Which of the following statements is not deductively valid?

• A)If people watch television,then they get a headache.They watch television.
• Therefore,they get a headache.
• B)If a student writes an abstract for a paper,then she gets a good grade.A student's paper is abstract.Therefore,the student gets a good grade.
• C)If the sky is clear,then there are no clouds.The sky is clear.Therefore,there are no clouds.
• D)If a black cat crosses your path,then you will have bad luck.A black cat crosses your path.Therefore,you will have bad luck.